When to Plant Hardy Hibiscus in Keene, NH

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Keene you will be able to determine when it's a good idea to plant hardy hibiscus.


Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Hardy Hibiscus can survive in a bit of cold which tells us that you can plant them earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hardy hibiscus
Possibly ok, but a risky time to plant hardy hibiscus
Probably not a good time to plant hardy hibiscus

The earliest that you can plant hardy hibiscus in Keene is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to really do well. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Keene. In the coldest months of winter you should expect an average low temperature of -15°F.

Always keep in mind that USDA zone info for Keene is an average and the actual date of last frost is different every year. Half of the time in Keene last frost occurs after April 15 so make sure that you are prepared to cover your hardy hibiscus if you have a late frost.

USDA Zone Info for Keene

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Keene

You may be interested in your other planting guides for Keene.